October 5, 2012

Adult Cells In The Brain Used To Generate Neurons

Difficulties in balance and movement, hesitation in breathing and talking are just a few of the detrimental effects of neurodegenerative disease, and the illness can sometimes be serious or even life threatening. In the research community, more studies are being done to understand how these disorders can be treated. In particular, a new study highlights how human neurons can be generated from adult cells in the brain. Researchers believe that the results of the study will help in developing cell-based therapies to treat neurodegenerative diseases like Alzheimer´s and Parkinson´s.

The team of scientists completed neuronal reprogramming of adult human brain pericytes by utilizing transcription factors Sox2 and Mash1. According to The Scientist, Sox2 was experimented on in mice to change a certain type of brain cells into neurons while Mash1 was used in changing skin cells into neurons. The study took place over a period of four to five weeks and the researchers documented the transformation of the cells with the help of a time-lapse video microscope.

“We believe that Mash1 and Sox2 superimpose a neuronal program onto a cell that has another program running,” Benedikt Berninger, lead author of the study, told The Scientist. “But we are keen to understand the exact mechanisms.”

Based on the results, the researchers found that the reprogramming of somatic cells into neurons could help develop cell-based therapy for neurodegenerative diseases. In particular, they found that cells from the cerebral cortex part of the brain could be reprogrammed into neuronal cells.

"This work aims at converting cells that are present throughout the brain but themselves are not nerve cells into neurons," said Berninger, a researcher currently at the Johannes Gutenberg University Mainz, in a prepared statement. "The ultimate goal we have in mind is that this may one day enable us to induce such conversion within the brain itself and thus provide a novel strategy for repairing the injured or diseased brain."

In particular, pericytes are the cells that were found to be able to move from one adult cell to human neuron. The cells, which are in close contact with blood vessels, help keep the blood-brain barrier together. Researchers also believe that the cells can be utilized in healing wounds in various parts of the body.

"Now, we reason, if we could target these cells and entice them to make nerve cells, we could take advantage of this injury response," continued Berninger in the statement.

Additional testing also showed that the neurons that were converted to adult cells could start up electrical signals. These signals could connect to other neurons and showed that converted cells could be added to neural networks. The researchers plan to investigate the various components of programming and how they can make it become more effective.

"While much needs to be learnt about adapting a direct neuronal reprogramming strategy to meaningful repair in vivo, our data provide strong support for the notion that neuronal reprogramming of cells of pericytic origin within the damaged brain may become a viable approach to replace degenerated neurons," concluded the researchers in the paper.

The findings were recently published in Cell Stem Cell, a Cell Press publication.